Amazon Cloud Outage Finally Explained

Turns out major web sites were knocked off-the-air by an upgrade Amazon was performing to its EC2/EBS service. Last Thursday’s outage caused sites including Foursquare, Reddit and Quora to go offline, some for days. Thousands of smaller web sites were off-line for much longer.

A statement on Amazon’s website said: “We know how critical our services are to our customers’ businesses and we will do everything we can to learn from this event and use it to drive improvement across our services.”

Amazon promised to “spend many hours over the coming days and weeks improving our understanding of the details of the various parts of this event and determining how to make changes to improve our services and processes”.